Crosstalk between nicotine and estrogen-induced estrogen receptor activation induces α9-nicotinic acetylcholine receptor expression in human breast cancer cells
Crosstalk between nicotine and estrogen-induced estrogen receptor activation induces α9-nicotinic acetylcholine receptor expression in human breast cancer cells
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DOI：
10.1007/s10549-010-1209-0
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发表时间：
2011-09-01
影响因子：
3.8
通讯作者：
Ho, Yuan-Soon
中科院分区：
文献类型：
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作者：
Lee, Chia-Hwa;Chang, Ya-Chieh;Ho, Yuan-Soon
本研究的主要目的是阐明雌激素受体（ER）的作用，ER是一种参与尼古丁和17 β-雌二醇（E2）介导的α 9-nAChR基因表达上调的转录因子。采用实时聚合酶链反应（PCR）分析定量手术分离（n = 339）和激光捕获显微切割组织（ER+ vs ER-，每组n = 6）的α 9-nAChR mRNA表达水平。染色质免疫沉淀（ChIP）和酶启动子活性测定用于研究ER介导的α 9-nAChR基因表达的转录调控。我们观察到具有较高α 9-nAChR mRNA表达水平的乳腺肿瘤（即，肿瘤/正常配对样本中的平均倍数比大于10倍）与最低的5年疾病特异性存活率（50%，死亡/存活= 4/4，总共= 8名患者，P = 0.006）相关，与低水平的乳腺肿瘤（即，α 9-nAChR表达的平均倍数比小于1倍）（88%，死亡/存活= 3/22，总共= 25名患者）。此外，与ER-肿瘤组织相比，在ER+肿瘤组织中优先检测到更高的α 9-nAChR mRNA表达水平（ER+与ER-患者：n = 160对72; α 9-nAChR表达的平均倍数比分别为11 +/-A3对6.7 +/-A2.3倍）。体外启动子结合试验表明，ER是一个主要的转录因子，介导尼古丁和E2诱导的MCF-7细胞α 9-nAChR基因表达上调。总之，我们的数据表明，ER在介导α 9-nAChR基因上调响应于尼古丁或E2刺激中起着核心作用。
The primary aim of this study was to elucidate the role of the estrogen receptor (ER), a transcription factor involved in the nicotine- and 17 beta-estradiol (E2)-mediated up-regulation of alpha 9-nAChR gene expression. A real-time polymerase chain reaction (PCR) assay was used to quantify the alpha 9-nAChR mRNA expression levels of surgically isolated (n = 339) and laser-capture microdissected tissues (ER+ versus ER-, n = 6 per group). Chromatin immunoprecipitation (ChIP) and luciferase-promoter activity assays were used to investigate the ER-mediated transcriptional regulation of alpha 9-nAChR gene expression. We observed that breast tumors with higher alpha 9-nAChR mRNA expression levels (i.e., a mean fold ratio in the tumor/normal-paired samples of greater than tenfold) were associated with the lowest 5-year disease-specific survival rate (50%, dead/alive = 4/4, total = 8 patients, P = 0.006), in contrast to breast tumors with low levels (i.e., a mean fold ratio of less than onefold) of alpha 9-nAChR expression (88%, dead/alive = 3/22, total = 25 patients). Furthermore, higher alpha 9-nAChR mRNA expression levels were preferentially detected in ER+ tumor tissues in comparison to ER- tumor tissues (ER+ versus ER- patients: n = 160 vs. 72; mean fold ratios of alpha 9-nAChR expression = 11 +/- A 3 vs. 6.7 +/- A 2.3 fold, respectively). In vitro promoter-binding assays demonstrated that the ER is a major transcription factor that mediates nicotine- and E2-induced up-regulation of alpha 9-nAChR gene expression in MCF-7 cells. In conclusion, our data indicate that the ER plays a central role in mediating alpha 9-nAChR gene up-regulation in response to either nicotine or E2 stimulation.